Testing machine



March 24 1925.

w. D. LA BATT ET AL TESTING mourns Filed Aug. 13, 1921' 2*Shoats-Shee'tl Marsh 21; 1925. 1,530,678

w. D. LA BATT ET AL TBSIING cums Filed-M 13, 1921. 2 Sheets-Sheet 2 Patented Mar. 24, l925.

UNITED STATES? PATENT OFFICE.

WILLIAM D. LA BAT'I. AND HANS SENGEBUSCH, OF CHICAGO, ILLINOIS, ASSIGNORS TO ELISE-IA J. CADY, OF OAK PARK, ILLINOIS.

TESTING MACHINE.

Application filed August 1 3, 1921. Serial no. 492,007.

To all whom it may concern:

Be it known, that we, VILLIAM D. LA Barr and Hans SENGEBUSOI-I, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, having jointly invented certain new and useful Improvements in Testing Machines, do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings.

The invention relates to certain new and useful improvements in machines for test-- ing the tensile strength of sheet materials, such as paper, and its primary object is to provide improved means for automatically controlling and operating the pressureclainp by which the material is held in place and the piston by which the stock-ruptur-' ing liquid is compressed against the elastic diaphragm operating on the material. Other objects and advantages are attained as will be manifest from the disclosure.

Machines for testing the tensile strength of materials of the type in which the strain of a body of liquid under pressure is exerted against an elastic diaphragm acting in a transverse direction against a small confined section or area of the fabricor stock, when hand operated have heretofore been found unreliable for determining the true tensile strength of the material, particularly withrespect to paper and paper stocks, owing to the fact that as the plunger or piston which exerts pressure on the liquid is manually operated, usually by a hand-wheel, the pres sure of the liquid on the diaphragm and so of the latter on the stock is not constant in its increase, but may be manipulated either by the slow rotation of the hand-wheel to produce a gradual tearing or delayed fracture of the stock or by its quick rotation to produce a premature fracture; thus adj acent portions of the same piece of stock may be fractured the one at a low pressure by slowly rotating the hand-wheel and the other at a high pressure by quickly rotating it. Also, in such prior machines as the stockclamp or pressure-foot is operated by a hand-wheel different samples of stock are held on the supporting-platform by different pressures, with the result that unless great care be taken to set the clamp down as tight as possible the material may be more or less displaced or drawn between the platform and clamp by the initial movement of the diaphragm to form a premature bulge over the diaphragm instead of presenting a surface of uniform tautness to it.

' By our present invention these defects are obviated, the machine is started by a manually-operated lever after which its stroke or cycle is entirely automatic, and it exerts a constant and uniform clamping pressure on the stock on the platform and a constant increase of pressure of the liquid on the stock-rupturing diaphragm, and after a test is made the pressure of the liquid on the diaphragm is released by reversing the lever, and all the pressure parts are automatically restored to their initial positions ready for a subsequent test. The invention further comprises certain organizations and arrangements of parts by which other novel and useful results and adavantages are obtained, as will appear from the description of the construction and mode of operation of its several features.

The invention consists in the matters hereinafter described and then Pointed out in the appended claims.

In the drawings Fig. 1 is a view partly in elevation and partly in section of a machine embodying the various features of our invention, the parts being shown in their positions of rest, and Fig. 2 is a similar view of the same parts as they appear when the machine is operating.

, In the drawings the reference numeral 1 represents the base and frame of the machine, and 2 a compression cylinder attached to and supported by the frame in any suitable manner and centrally bored throughout its length, with one end upturned as shown to form a vertical branch 3 which is bored and has an open end closed. by the diaphragm 4 of elastic material as now well-understood in the art. The vertical branch is threaded to receive a cap 5 which holds the diaphragm in position and forms a stock-supporting platform, the

The

pressure of the fluid in the chamber and indicating the pressure by its pointer on its dial in pounds and fractions thereof in the usual manner. The opposite end of the cylinder is enlarged to form a piston chamber 9 into which the lower end of the piston 10 enters, and this chamber has a by-pass 11 near its upper end leading to a plungerchamber 12 which in turn communicates at its lower end with an expansion chamber 13 for the rupturing liquid. The cylinder and piston-chamber form a pressure-chamber for the rupturing liquid, and the chainber 9 is provided with an anuular bushing 14 within the bore of which the piston 10 reciprocates and thus acts as a valve to establish and cut-off communication between the pressure-chamber and the expansion chamber, and the plunger-chamber 12 is provided with an annular bushing 15 within. the bore of which the plunger 16 reciprocates to open and close the by-pass '11, the upper ends of these bushings being provided with siiitablepacking boxes or glands. The cylinder 2, branch v3, chambers 9, 12 and 13, by-pass 'lland the bushings 14 and 15 are all formed in a suitable block or casting 17, and the chamber 12 is provided with a screwbap 18 so that the interior parts may be supplied with a suitable quantity of glycerin or otherliquid asshown. In practice this liquid'does not'e'ntirely fill tlie'eX- pansion chamber, but preferablyis sufficient to cause its head in the branch ,3 to be flush against the diaphragm whenv the parts are in their normal positiohs.

The plunger '16'is pivotally connected by a link 19 to one arm 20 of afbell-crank lever pivoted on the frame at 21 and extendedupwardly into a starting lever '22, and the other arm'23 of the bell-erank'lever is connected to one endof'a coiled sprinie' 24 whose other end isattache'd to a pin 25 on a clamp-operating lever 26 which is pivoted on a rod or 'pintle 27 at a point above and'slightly off-set from the axial line of the vertical branch 3 an'c l platform 5. A pressure-foot consisting of opposite converging spider arms 28 and an annular stoekclamp '29 adapted to register with theplatform around its opening and having a central aperture of the sar'ne diameter as the mouth "6 of'the platform, is suspended in line above the platform by having its upper member 30 pivoted at 31 to the outer-"arm of a pressurelever 32pivoted on the pintle 27. The stock-clamp and its operating lever 26 have a spring-connection,for which purpose the lower face of the inner arm of the lever 32 is provided with a socket 33 to receive one end of a coil-spring 34 which reacts between 'the'levers 26' and 32,'these parts being connected in operativerelation by the headed bolt 35 passing freely through the lever 32 and having its inner end threaded to adjustably engage the lever '26.

Bythis' means the lever 32 is spring-pressed, and the spring is set to give the desired pres sure on the pressure-foot, it being obvious that the force of the spring may be adjusted by adjusting the socket-bolt in the lever 26. The opposite end of the lever 26 is provided with a segmentalv notched rack 36 adapted to be engaged by a pawl 37 which is held normally out of engagement with the rack by a distance pin 38 and is pivoted near its lower end to a pawloperating lever 39 which is pivoted on the frame at 40, the pawl 37 being spring-actuated by a spring 41 connecting its lower end to the lever 39 to urge its upper or pawl-end toward the rack.

A shaft 42 is jour'naled in the frame and carries a worm-wheel '43 which is driven in the direction of the arrow by a worm-gear 44 one shaft 45 which carriesa fixed pin'ion 46 in enfgagen'ient with a driving pinion 4-7 on thesha'ft of an electricmotor 48 which is included in a s'uitable'electriccircuit deriving its current from anysuitable source of power. The shaft is preferably driven by aniotor having a constant speed so that when the shaft rotates a constant pressure is obtained for andexerted by'the pressure foot and the pressure-piston. The 'motor circuit ii'i'cludesa switch having a fixed con tact 49 andaspring-contact 50 actuated-by a suitably insulated eonnection'bythe l'o'wer end' of therack'36 and'having'a contracting spring 51t'ending'toclose'the contacts. The shaft 42 carries a fi'Xe'd'cam-wheel 52 having a "concentric operative contour and a dwell or hatch 5'3 and wiping against an anti-friction disk 54 mounted on the end of the lever 39 opposite the pawl 37. T he lever '39 "carries a liked "arm 55 extending i"ea'r'wardly andconnectedto one'end of a retracting spring '56 whose other end is anchored to the frame at 57 whereby the disk 54 is held in operative position against the cam-wheel 'The shaft 42 also carries a fixed spiral cam-wheel'oS which wipes against an ant-i-frietion disk 59 carried on one end of the piston-z'ictuating lever (30 whieh'is pivoted o'n theframe at 6l with. its forward-end pivoted at G2to a piston-link 63 and its rear endcoi'ineete'df to one end of a retracting spring 64 whose other "end is anchored to the frai'n'e at 57.

urea the niacliihe isat rest the parts are in the pos'itio ns shown in Fig. 1. lV'h'en a piece of stock '8" to be tested is placed on the stock platform 5 the operator turns the .st-artingi-lever the diretti'on shown in Fig. 2fimtil itsabut's a gz'iinst the 'stop'65. The initial movement of the starting-lever depresses the lunger-1'6 to close theby-pass 11 to seal the"pressure-chamber and isolate the liquid in it from the efipansion "chamber, audit-also raises the lever 26 tos'et the pressure-foot to its "initial operative position but down on the stock on the platform and to close the switch of the motor circuit to cause current to flow through the motor. The shaft t) is driven by the motor in the direction or its arrow, and its rotation causes the cam-wheel 52 to rock the lever 39 on its pivot to project the pawl 37 into engagement with the rack to interlock these parts and rock the lever 26 to mechanically clamp the pres sure-toot hard against the stock on the platform 5, the pressure of the foot being uniform and constant during the stroke of the cam of the wheel which is proportioned to hold the pressure-foot down with sulficient force to prevent the displacement of the stock between the platform and foot by the subsequent distending of the diaphragm. The rotation of the shaft subsequently causes the spiral-cam 58 to rock the pistonlever (30 on its pivot to drive the piston 10 into the body of liquid contained in the pressure-chamber, thereby displacing it and compressing it in the bore 3 to upwardly distend the diaphragm against that portion of the stock underlying the aperture in the clamp 29 until it ruptures, the pressure of the liquid on the stock being constant and of uniformly increasing force until it reaches its peak so that the rupture occurs normally and naturally when the true limit of its tensile strength is'reached, the gage registering the exact amount of pressure existing at the instant the rupture occurs. The spiral cam 58 is proportioned to operate the piston to exert a final or peak pressure on thediaphragm suilicient to rupture stock of maximum tensile strength in the class of goods or material to be tested when the high end of the cam reaches the disk 59, so that the distention of the diaphragm is suflicie-nt to make the test on material of normal standard strength before the peak is reached. The open end of the compression chamber is rounded or spherical about its bore to form a convex seat for the diaphragm corresponding to the bell-mouth of the cap 5 to hold the diaphragm in. its inoperative or normal position in the bell-moutl'i app-roximately flush with the line of the stock, so that the diaphragm exerts its pressure on the stock from the beginning of the stroke of the piston and is not compelled. to rise through. the cap before beginning its pressure. The cap 5 effects a liquid-tight joint between the diaphragm and chamber, and its bell-shaped mouth presents a curved surface above the operative central portion of the diaphragm so that the normal position of the cliaphragm before its distention will be approximately at its working level against the stock and the resistance of the cap to the action of the diaphragm is eliminated, and the only pressure established in the chamber and registered on the gauge is thatactually required to disrupt the fabric. The operative positions of the parts during a portion of the stroke or cycle of the machine are shown in Fig. 2. The cycle of the machine is such that it runs until the pressure mechanism reaches its peak, then all the parts return. to their normal or zero positions and the machine automatically stops,

and the distention of the diaphragm can be released when the test occurs before the inachine completes its cycle.

When the stock ruptures the startinglever is reversed or returned to its initial position; its return movement raises the plunger 16 to open the bypass to release the pressure in the compression chamber and relieve the pressure of the liquid on the diphragm to allow the latter to immediately cease its distention and resume its normal position so that during the completion of the stroke of the spiral-cam in the cycle of the machine the diaphragm will not be further or unnecessarily distended. The spring-connection at 24 between the starting handle 22 and the clamp lever 26 enables the operator to reverse the handle to release the pressure on the diaphragm as soon as a test is made, so that it is not held distended during the cycle of the machine. When the handle is reversed the spring Ql takes up the motion between its arm 23 and the lever 26, so that the latter is not moved and the clamp is held down on the stock and the switch is held closed by the engagement of the parts 86 and 37 until the shaft completes its revolution, and then the dwell in the cam-wheel 52 releases this engagement to permit the clamp to recede from the stock and the switch to open to stop the o-peration'of the machine; the stockclamp remains in operative position and the piston 10 completes its stroke after the handle is reversed, but that part ofits stroke made after the rupture occures and the handle is reversed produces no pressure on the diaphragm as the retraction of the plunger 16 by the handle opens the by-pass and places the pressure-chamber in communication with the expansion-cl'iamber into which the liquid then expands or flows from the pressure-chamber. By this arrangement the diaphragm is protected against unnecessary distention and its life is prolonged. The spiral cam is provided with a quick offset or drop to release its pressure on the disk 59 and permit a quick return of the lever 60 to its inoperative position by the spring 64 after the shaft has made its revolution, thereby retracting the piston 10 and with-- drawing its pressure on the liquid. The parts are arranged so that when the dwell or drop of the cam 58 reaches the disk 59 the notch 53 in the cam-wheel 52 regis ters with the disk S lwhereby the lever 39 is released from the wiping action of the 'am and its spring 56 retracts it to the posi tion shown in Fig. 1 to withdraw the pawl 37 from the rack 36, thereby permitting the lever 26 to fall to its normal'position by gravity and under the impetus of a spring 66 to open the motor circuit. lV'hen the motor stops the pressure-foot and piston with their associated parts are all in their initial or normal positions. The operator merely rocks the starting lever, and the flow of current through the constant-speed motor causes the machine to exert a constant and uniform pressure on the stock clamp and a constant and uniformly increasing pressure on the diaphragm, and after the rupture of the stock occurs all the pressure parts are restored to position for another test. The provision of a spring-connection between the stock-clamp and its pressure lever 26 is advantageous as it provides a safety device that. prevents the pressure of the clamp on the stock being greater than the force which the spring allows; the travel imparted mechanically to the clamp by the cam 52 is limited or restricted to a distance that will set up sufficient clamping pressure to hold soft stocks without affecting their normal resistance to the action of the diaphragm, and when denser or more solid stock is tested the cam throws the lever 26 but the relatively greater resistance of such stock will prevent the clamp from going to its full distance or travel, and this differ ence is taken up or compensated for by the spring 34. Thisconstruction allows a predetermined clamp pressure to be set up by the spring 34 and stopped after the clamp has traveled a predetermined distance, so that clamping of soft or easily crushable fabrics and hard fabrics or stock can be accomplished without any change or readjustment of the clamping parts.

lVe claim:

1. In a machiire for testing fabrics, a compresssion chamber containing a liquid and having a stock-rupturing diaphragm closing its end, an apertured fabric-support, a fabric clamp, means to set the clamp on the stock, a piston for imparting pressure on the liquid in the chamber, a shaft rotating at constant speed, and mechanical connections between the shaft and clamp constructed to impart uniform pressure by the clamp on the stock upon the rotation of the shaft.

2. In a machine for testing fabrics, a compression chamber containing a liquid and having a stock-rupturing diaphragm closing its end, an apertured fabric-support, a fabric clamp, a handle to set the clamp on the stock on the support, means to adjust the pressure of the clamp, a piston for imparting pressurc'on the liquid in the chamber, a shaft rotating at constant speed, and mechanical connections between the shaft and clamp constructed to impart uniform pressure by the clamp on the stock upon the rotation of the shaft.

8. In a machinle for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an apervured fabric-support, a movable fabric clamp, a shaft, a motor to rotate the'sliaft, switch mechanism for the motor, a handle to set the clamp to its initial operative position and close the switch, and connections between the shaft and clamp to i'ncchanically operate the clamp upon the rotation of the shaft.

i. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing itsend, an apertured fabric-support, a movable fabric clamp, a shaft, a motor to rotate the shaft, switch mechanism for the motor, a lever to operate the clamp and control the switch, a handle having a spring-connection with the lever to close the switch and set the clamp to its initial operative position, and connec tions' between the shaft and lever to mechan ically operate the clamp upon the rotation of the shaft.

5. In a machine for testing fabrics, a. compression chamber containing a liquid and havinga diaphragm closing its end, an apertured fabric-support, a movable fabric clamp, a shaft, a motor to rotate the shaft, switch mechanism for the motor, a lever to operate the clamp and control the switch, a handle to move the lever to close the switch and set the clamp to its initial operative position, a second lever operated by the shaft, and means to interlock the le'vers to mechanically operate the clamp upon the rotation of the shaft.

'6. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an apertured fabric-support, a movable fabricclarnp, a cam-shaft, a motor to rotate the shaft, switch mechanism for the motor, a lever to operate the clamp and control the switch, a handle to move the lever to close the switch and set the clamp to its initial operative position, a second lever operated by the cam-shaft, and ratchet conneutious between the lovers 'to mechanically operate the clamp upon the rotation of the shaft.

7. In a machine for testing fabrics, a compression chamber containing a liquid. and having a stock-rupturing diaphragm closing its end, an apertured fabric-support, a fabric clamp, a piston for imparting pressure on the liquid, a shaft, an electric-motor to drive the shaft, mechanical means be tween the shaft and clamp and between the shaft and piston to operate the clamp and piston upon the rotation of the shaft, a switch for the motor circuit controlled by the clamp-operating means, and automatic means to disconnect the clamp operating means and open the switch when the shaft completes its rotation.

8. In a machine for testing fabrics, a) compression chamber containing a liquid and having a diaphragm, a fabric clamp, a piston for imparting pressure on the liquid in the chamber, a shaft having a cam to actuate the piston, an electric-motor to drive the shaft, a switch for the motor circuit, a clamp and switch controlling member, and means actuated by the shaft toengage said member upon the rotation of the shaft and to release it when the shaft completes its rotation.

9. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an expansion chamber communicating with the compression chamber, a piston for imparting pressure on the liquid, and a manually operated valve controlling the communication between the chambers for releasing the pressure in the compression chamber when thetest occurs before the piston completes its stroke.

10. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an expansion chamber having a bypass from the compression chamber, a piston for imparting pressure on the liquid, a plunger to open and close the by-pass, and a handle connected to the plunger.

11. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an expansion chamber communicating with the COIHPlGSSlOll chamber, a valve controlling the communication between the chambers, a piston for imparting pressure on the liquid, a shaft, a motor to rotate the shaft, switch mechanism for the motor, connections between the shaft and piston to impart motion to the piston upon the rotation of the shaft, a handle connected to the valve, and a spring-connection between the handle and switch.

'12. In a machine for testing fabrics, a compression chamber provided with a by pass and having a stock-rupturing diaphragm closing its end, an apertured V falnic-support, a fabric clamp, a piston for imparting pressure on the liquid, a shaft, an electric motor to drive the shaft, a switch for the motor circuit, connections between the shaft and clamp and between the shaft and piston to operate the clamp and piston upon the rotation of the shaft, a plunger controlling the bypass, a lever to protract the plunger to close the by-pass and control the switch, and automatic means to open the switch and retract the plunger when the shaft completes its rotation.

.13. In a machine for testing fabrics, a compression hamber provided with a bypass and having a stock'rupturing diaphragm closing its end, an apertured fabric-support, a fabric clamp, a piston for imparting pressure on the liquid. a plunger controlling the by-pass, a shaft carrying a notched cam Wheel and a spiral cam with a quick drop, a spring-stressed piston-lever cont-rolled by the cam, a clamp-lever having a rack, a spring-stressed pawl adjacent the rack, a spring-stressed pawlcperating lever controlled by the cam wheel, a handle to operate the clamp lever and plunger, a motor to drive the shaft, and a switch for the motor circuit controlled by the handle.

14. In a machine for testing fabrics, a compression chamber containing a liquid and having a stock-rupturing diaphragm closing its end, an apertured fabric-support, a fabric clamp, a piston for imparting pressure on the liquid, a shaft, an electric-motor to drive the shaft, means to cause the clamp and piston to function during each rotation of the shaft, manually operated means to release the pressure in the chamber when the test occurs before the piston completes its stroke, and means to withdraw the clamp and piston upon the completion of the shafts rotation.

15. In a machine for testing fabrics, a compression chamber containing a liquid and having a stock-rupturing diaphragm closing its end, a piston for imparting pressure on the liquid, a shaft, an electric-motor to drive the shaft at constant speed, connec tions between the shaft and piston to oper ate the piston upon the rotation of the shaft, a switch for the motor circuit, connections between the switch and shaft to open the switch when the shaft completes its rotation, and manually controlled means to release the pressure on the liquid before the switch is opened.

16. In a machine for testing fabrics, a compression chamber containing a liquid and having a stock-rupturing diaphragm closing its end, an apertured fabric-support,

I a fabric clamp, a handle to set the clamp on the stock on the support, means to adjust the pressure of the clamp, a piston for imparting pressure on the liquid in the chamber, a shaft rotating at constant speed, connections between the shaft and piston to operate the piston upon the rotation of the shaft, and means operated by the handle 'to release the pressure on the liquid before the shaft completes its revolution.

17. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, an apertured fabric support, a pressure-foot, a lever controlling the foot, an adjustable spring-connection between the lever and foot, a piston in the compression chamber,

and means to simultaneously operate the piston and lever.

lill) 18. Inv a machine for testing fabrics, a compression chamber containing a liquid and having a convex end, a diaphragm closing its end, adiaphragm-clamp having a bell-shaped mouth, a fabric clamp, a piston in the chamber for imparting pressure on the liquid, and means to operate the fabric clamp and piston.

19. In a machine for testing fabrics, a compression chamber containing a liquid and having a diaphragm closing its end, a diaphragm-clamp having a bellshaped mouth presenting a curved surface above the operative portion of the diaphragm, a fabric clam a piston for imparting pressure on the iquid, and means to operate the fabric clamp and piston.

20. In a machine for testing fabrics, a

compression chamber containing a liquid and having a stock-ruptiwing' diaphragm closing its end, a piston for imparting pres sure on the liquid, a shaft, an electric-motor to drive the shaft at constant speed, connections between the shaft and piston to protract the piston during each rotation of the shaft, a switch for the motor circuit, connections between the switch and shaft to open the switch when the shaft completes WILLIAM D. LA BATT. HANS SENGEBUSCH. 

